Speed-changing device.



- PATENTED JAN. 20, 1903.

J. H. & H. H. DOW.

a. J. now, BXEOUTEIX or J. n. DOW, DEOD..

SPEED CHANGING DEVICE.

APPLICATION rum) MAY 1; 1901.

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No. 718,922. PATENTED JAN. 20, 1903.

" J. H. & H. H. DOW.

S. J. DOW, EXEOUTRIX OF .T. E. DOW, DEO'D.

SPEED CHANGING DEVICE.

APPLIOAT n 1, 1901. no MODEL. I:fE+'E&Y- 2 SHEETS-SHEET 2.

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lUni'rnn Trnrns PATENT OFFICE.

SARAH J. DOW, EXEOUTRIX OF JOSEPH H. DOW, DECEASED, AND HERBERT H. DOW,OF MIDLAND, MICHIGAN.

SPEED-CHANGING DEVICE.

SELEJGIFIZGATIOH forming part of Letters Patent No. 718,922, datedJanuary 20, 1903.

Application filed May 1,1901. Serial No. 58,366. (No model.)

To aZZ whom, it may concern:

Be it known that we, JOSEPH H. DOW, deceased, and HERBERT H. Dow, acitizen of the United States, and a resident of Midland,

county of Midland, and State of Michigan, have invented anew and usefulImprovement in Speed-Changing Devices, of which the following is aspecification; the principle of the invention being herein explained,andthe best mode in which the above have contemplated applying thatprinciple, so as to distinguish it from other inventions.

The object of the invention is to provide means for transmitting motionfrom a rotating shaft having an excessively high speed through themedium of mechanism whereby the power from such shaft may be transmittedat a comparative low speed.

Said invention consists of means hereinaf- 2o ter fully described, andspecifically pointed out in the claims.

The annexed drawings and the following description set forth in detailcertain mechanism embodying the invention, such disclosed meansconstituting but one of various mechanical forms in which the principleof the invention may be used.

In said annexed drawings, Figure I represents a front elevation of adevice embodying the invention. Fig. II represents an end elevationillustrating a portion broken away. Fig. III represents a transversesection taken upon the line 3 8 of Fig. I, showing parts in elevation.Fig. IV represents a vertical section taken upon the plane indicated byline at 4:, Fig. III; and Fig. V, an end elevation.

Upon a frame A are bolted two supportingrods A, which projecthorizontally on such frame, as shown in Figs. II and III. To the innerextremities of said rods is secured by means of suitable nuts a plate AFig. III, at the upper portion of which is secured the inner end of arod A the outer end of such rod being secured in the frame A, as shownin 45 Fig. III. The relative position of frame A and plate A ismaintained by means of tubular separators (4. Upon said rod is journaleda roller 13, having a cylindrical contact-surface Z), upon which restsan interior cylindrical contact-surface c of a rotatable drum 0. In thelower portion of frame A is journaled a rock-shaft D, whose innerextremity is journaled in the lower portion of the plate A as shown inFig. III. Upon said shaft are secured two rocking arms (I d, to whoseextremities are respectively journaled the extremities of two links 61'd. Upon the other extremities of these links is mounted a rod E, andjournaled upon said rod intermediate of the two links is a roller E.Upon the extreme outer end of said shaft D is secured the end of a leverF, Fig. I. Athird journal-rod G has its extremities in the plate andframe, respectively, and forms a bearing for a third roller G, Fig. I.The diameters of rollers E 65 and G are preferably made equal, thediameter of roller B being made greater than that of roller E. The innerdiameter of the contact-surface cof the rotatable drum (3 is madesubstantially equal to the diameter of the cyl- 7o inder determined bythe extreme outer elements of the contact-surface of said rollers B,

E, and G. A driving-shaft H, from which it is desired to transmit powerat lower speed, projects between the three above-named rollers, asshown, and is of a diameter substantially equal to that of the cylinderdetermined by the extreme innermost elements of the contactsurfaces ofsaid rollers, whereby said shaft may be caused to contact the surfacesof said three rollers simultaneously. The diameter of roller E is causedto be greater than the difference between the radius of the cylindricalcontact-surface of the drum and the sum of the radius of shaft H and theeccentricity of said drum-surface relatively to theshaft-surface,whereby it is seen that the roller E, being mounted upon amovable axis, may

be caused to contact the shaft-surface and cylindrical drum-surface bymoving said roller downwardly. Such effect is produced as a result ofthe relative location of the shaft and drum surfaces, these two surfacesapproaching each other in the direction in which said movable roller ismoved. The central portion of the drum 0 is provided with a squareaperture c, in which may be inserted-a shaft to i which itis desired totransmit the power. Said drum is steadied in its movement by means of acylindrical washer a, which bears in a cy- 10o lindrical bearin g formedat the inner end of said aperture 0, as shown in Fig. III.

A spring J may be operatively connected with the outer end of the leverF to maintain normal operative contact between the movable roller E andthe shaft and drum, as shown.

In operating the device the spring J is made sufliciently strong so asto maintain operative contact, as above described, and the direction ofrotation of the shaft is that indicated by the arrow in Fig. I-that is,a direction such that the roller E will not cause a Wedging between theshaft and drum surfaces during rotation. Such Wedging would result ifthe direction of rotation were opposite that shown, as will be readilyunderstood.

When a spring such as is described is utilized, the tension thereof maybe such as to normally maintain operative contact between the shaft androllers, so that when it is desired to disconnect the speed-changingdevice from the shaft it is only necessary to lift the lever F by handor by any suitable lever against the action of said spring sufficientlyto reduce the frictional contact to a degree insufficient to effect suchoperative contact. When the load is considerable, such lifting need bebut very slight to effect the disconnection, and when the required speedhas been attained lever F is released to permit the spring J to resumeits tension.

Other modes of applying the principle of the invention maybe employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any one of the followingclaims or the equivalent of such stated means be employed.

What is therefore particularly pointed out and distinctly claimed is- 1.In a speed-changing device, the combination with a rotatable drum,having an inner contact-surface, of a shaft; two rollers mounted onfixed axes, and in contact with said shaft, and drum, and a thirdroller, mounted on swinging bearings, and normally in contact with saidshaft, and drum, and adapted to be moved out of contact with the shaft;one of the rollers on the fixed axes,

having a larger diameter than the other two rollers, as herein setforth.

2. In a speed-changing device, the combination with a rotatable drum,having an inner contact-surface, of a shaft, eccentric to the axis ofthe drum; three rollers in contact with said shaft, and drum, two ofsaid rollers having fixed axes, and the third mounted in swingingbearings, and normally in contact with said shaft, and drum, and adaptedto be moved out of contact with the shaft; the diameter of one of therollers on the fixed axes being larger than that of the other two, asherein set forth.

3. In a speed-changing device, the combination with a rotatable drum,having an inner contact-surface, of a shaft; a third roller, normally incontact with said shaft, and drum, and movable out of contact with theshaft; a rock-shaft, having rocking arms, links on which the thirdroller is mounted connected with said rocking arms, and means wherebythe third roller may be moved out of contact with the shaft,substantially as set forth.

Signed by us this 29th day of April, 1901.

SARAH J. DOW, Executrt'x of the estate of Joseph H Dow, de-

ceased.

HERBERT I-I. DOW. Attest:

MARIA H. Dow, FLORA M. THOMPSON.

